1. Field of the Invention
The invention relates to cooling devices, in particular evaporative coolers, and more particularly to a dew-point cooler, having provisions to reduce the effects of microbial contamination.
2. Description of the Related Art
An evaporative cooler is a cooling device using the evaporation of a vaporizable liquid, in particular water, in order to achieve a cooling effect on an air stream which is to be cooled. To this end, two thermally coupled medium circuits are used, the circuits being at least partially separated by a heat transmitting partition. A first medium to be cooled flows through the first medium circuit and a second medium flows through the second medium circuit. Evaporation of a liquid present on the surface of said partition into the second medium cools the partition and absorbs heat from the first medium. Particularly efficient operation is achieved by using as the second medium, a part of the first medium after it has passed over the partition. An evaporative cooler of the dew-point type is known from WO03091633.
To achieve a substantial cooling effect, use can be made of a coating that is applied onto the heat exchanging partition and/or heat conducting elements connected with the partition, such as fins, and which is suitable for absorbing and dissipating a liquid that is added to the coating. Optionally, it is possible to use collecting means, such as a container, for the collection of surplus, non-evaporated water that could be reinserted into the cooling water circuit.
A known disadvantage of this kind of device is that they are susceptible to microbiological contamination on wet surfaces or in said liquid, including bacteria, viruses, algae, moulds and other micro-organisms. It has been shown that such contamination is particularly problematic in cases where the wet surfaces are coated with natural or semi-natural materials such as cotton, wool, viscose and the like.